マイクロ波プラズマＣＶＤ法による傾斜機能皮膜の作製 酸化シリコン皮膜の表面はっ水化

Abstract

We prepared transparent and hard silicon oxide films having water-repellent surfaces. In the multiple-step microwave plasma-enhanced chemical vapor deposition (MW PECVD) we developed, silicon oxide layer was prepared using mixture of tetrametylsilane (TMS) or tetramethoxysilane (TMOS) and oxygen (O2) as source gases. Next, O2 was exchanged to FAS-17 ((heptadecafluoro-1, 1, 2, 2, tetrahydro-decyl)-1-trimethoxysilane). We introduced FAS-17/Ar into the reactor using Ar as the carrier gas. The O2 supply decreased gradually, then was depleted. Al-10min water-repellent layer was deposited after TMS or TMOS partial pressure was adjusted to equal that of FAS-17/Ar. The contact angles obtained depend strongly on organosilicon compounds and substrate temperatures. Silicon oxide film surfaces treated with TMS without methoxy groups and FAS-17/Ar at 70°C had high water-contact angle of 120 degrees. The water repellency of films obtained by multistep CVD was inferior to that of single layers of water-repellent films prepared from TMS and FAS-17/Ar without O2 in the first step of film preparation. Residual oxygen in the reactor oxidized the water-repellent layer, reducing the hydrophobic properties of the surface. The ultramicrohardness of the silicon oxide films having water-repellent surfaces depended on the thickness of the water-repellent layer. The carbon concentration of films obtained in the multistep CVD gradually decreased from the surfaces to the insides, i. e., surfaces showed an organic nature even though inner regions were inorganic.